1. Field of the Invention
This invention relates broadly to roof drain covers. More particularly, this invention relates to roof drain covers that are adapted to remain clog-free.
2. State of the Art
Industrial and commercial buildings often have flat roofs. These roofs are provided with drains to remove standing water. The drains are provided with covers to catch leaves and other debris and prevent the debris from entering and clogging the drain pipe. The covers are typically hat-shaped grates or strainers defined by upright sidewalls having vertical slots through which water may exit into the drain. The slotted side walls prevent the passage of debris.
When debris flows-toward the drain and is stopped by the cover, the debris tends to clog the cover and prevent even the passage of water from the roof into the drain. This causes water to pool on the roof about the drain, and may result in roof damage, leaks into the interior of the building, and water pouring over the side of the building.
It is therefore an object of the invention to provide a drain cover assembly which is not susceptible to clogging.
It is another object of the invention to provide an anti-clog assembly which may be retrofit to an existing drain.
It is a further object of the invention to provide a retrofittable anti-clog assembly which is relatively easy to install.
In accord with these objects, which will be discussed in detail below, a clog-free roof drain cover assembly includes a first drain cover fixed over the drain, and a second drain cover be which is vertically movable relative to the first drain cover. The second drain cover includes a base provided with a plurality of weep holes, a debris skirt located above the weep holes, an upstanding preferably frustoconical hat-shaped portion provided with preferably vertical slots, and a closed-cell foam ring about the hat-shaped portion.
During light rains, water flows under the debris skirt and through the weep holes, into the first drain cover, and into the drain. During heavy rains, debris that normally clogs a fixed roof drain gets caught in the debris skirt and vertical openings of the second drain cover. When the pooling water reaches the level of the closed cell foam ring, the second drain cover begins to float, and the debris skirt thereon lifts the debris about the drain thereby allowing water to pass freely underneath, through the first drain cover, and down the drain.
The clog-free drain cover assembly may be installed during new construction or replacement roof work. Alternatively, it is appreciated that a retrofit assembly may be provided for use with existing roof drains covers. That is, in a retrofit assembly, existing drain covers comprise the first drain cover of the clog-free drain cover assembly, and the second drain cover and means for mounting the second drain cover over the first drain cover such that the second drain cover may move vertically relative to the first drain cover are additionally provided.